If you're not using the new Homegroup feature in Windows 7, or you've only got a single PC, you can disable the Homegroup feature to save memory and get rid of the items in the navigation pane.

Over at the How-To Geek site (my home away from Lifehacker), we've written up a quick guide to getting rid of the Homegroup feature—which is normally used for sharing files and printers between Windows 7 PCs—to save some system resources and get rid of a feature that you don't necessarily need if you only have a single PC. To disable for yourself, head into the Homegroup settings and use the Leave Homegroup option, and then disable the Homegroup Listener and Homegroup Provider services to remove the icons in the navigation pane. Hit the link for the full walk-through guide.